Chiapas Massif Research Articles

New insights into the history and origin of the southern Maya block, SE México: U–Pb–SHRIMP zircon geochronology from metamorphic rocks of the Chiapas massif

The histories of the pre-Mesozoic landmasses in southern Mexico and their connections with Laurentia, Gondwana, and among themselves are crucial for the understanding of the Late Paleozoic assembly of Pangea. The Permian igneous and metamorphic rocks from the Chiapas massif as part of the southern Maya block, Mexico, were dated by U–Pb zircon geochronology employing the SHRIMP (sensitive high resolution ion microprobe) facility at Stanford University. The Chiapas massif is composed of deformed granitoids and orthogneisses with inliers of metasedimentary rocks. SHRIMP data from an anatectic orthogneiss demonstrate that the Chiapas massif was part of a Permian (∼ 272 Ma) active continental margin established on the Pacific margin of Gondwana after the Ouachita orogeny. Latest Permian (252–254 Ma) medium- to high-grade metamorphism and deformation affected the entire Chiapas massif, resulting in anatexis and intrusion of syntectonic granitoids. This unique orogenic event is interpreted as the result of compression due to flat subduction and accretionary tectonics. SHRIMP data of zircon cores from a metapelite from the NE Chiapas massif yielded a single Grenvillian source for sediments. The majority of the zircon cores from a para-amphibolite from the SE part of the massif yielded either 1.0–1.2 or 1.4–1.5 Ga sources, indicating provenance from South American Sunsas and Rondonian-San Ignacio provinces.

A Late Permian Tectonothermal Event in Grenville Crust of the Southern Maya Terrane: U-Pb Zircon Ages from the Chiapas Massif, Southeastern Mexico

The Chiapas massif (CM) in southeastern Mexico is the crystalline basement of the southern Maya terrane, which is a crustal block that comprises mainly the Yucatan Peninsula, the Mexican states of Chiapas, Veracruz, and parts of Oaxaca. The CM is composed of igneous rocks and mediumto high-grade metamorphic rocks. Zircon fractions from all samples are discordant, yielding Late Permian lower-intercept ages and >1 Ga upper-intercept ages. The most precise results are from an orthogneiss that yielded intercept ages of 258.4 ± 1.9 Ma and 1046.6 ± 5.6 Ma, and from two augen gneisses which yielded intercepts of 250.9 ± 2.3 Ma and 1017 ± 27 Ma. We interpret the lower intercepts as either igneous crystallization or metamorphic ages and the upper intercepts as the age of inherited components. Results from all other samples are within error of these ages. These results demonstrate that the CM basement contains a Grenvillian component, and that the most important tectonothermal event affecting the CM was of Late Permian age. The results favor a hypothetical model in which the Maya terrane is composed of separated blocks of different geologic histories.

The Chiapas Massif (Mexico) revised: New geologic and isotopic data and basement characteristics

The Chiapas Massif (Mexico) revised: New geologic and isotopic data and basement characteristics

Distribution des sédiments sur la marge du golfe de Tehuantepec (Pacifique Oriental). Exemple d'interaction tectonique-eustatisme

During the PROGEMA I cruise which took place on the south-western Pacific coast of Mexico (between 14° and 16° N, 92° and 96° W), 3.5 kHz echosounding profiles, surface samples and cores as well as hydrological and oxygen minimum measurements down to 2250 m water depth were made in the Gulf of Tehuantepec. Chemical, sedimentological, mineralogical, X-ray and BEM analyses of waters, core and surface samples provided new data which permit a better knowledge of the Gulf of Tehuantepec margin, where tectonic activity is due to an active subduction. On the shelf of the gulf, the distribution pattern of quaternary deposits is affected by a double tectonic forcing and by eustatic oscillations of the sea level. The first tectonic control is linked to the existence of north-south tectonic troughs in the Tehuantepec Isthmus, in which the atmospheric circulation between the Gulfs of Mexico and Tehuantepec is accelerated by the Venturi effect. The resulting winds, called “Tehuanos”, play an important role in the forcing of surface circulation in the Gulf of Tehuantepec, inducing a deviation of the general circulation and thus forcing the distribution pattern of terrigenous sediment supply according to two physiographically and mineralogically distinct provinces, inherited from the past tectonic evolution, which are separated by the Tehuantepec axis. • -|A southeastern province related to the Caribbean Plate and fed by: (1) the rivers draining the Chiapas Massif; and (2) the Costa-Rica Current driving tropical and subtropical waters from Central America. • -|A northwestern province part of the North American Plate and fed by: (1) the Rio Tehuantepec which drains the Sierra de Oaxaca; and (2) the Californian Current. The second tectonic control is linked to the tectonic structure of the margin influenced by: • -|shallow banks where the products of a present-day phosphatogenesis are concentrated because they are swept by upwellings. The latter are reinforced because the banks are situated south of the wind corridor; • -|tectonic depressions acting as sediment traps; • -|numerous canyons cutting the slope along brittle accidents, driving weak turbidity currents but which play an important role in the forcing of upwelling currents. Antarctic diatoms are found which are conveyed by the deep circulation from the South-Eastern Pacific and provide evidence that Antarctic Cold Water masses (AABW) rise towards the shelf. The influence of eustatism is attested by the presence on the shelf of the Gulf of Tehuantepec of three paleoshorelines at 40 , 75 and 130 m water depth, linked to the Würmian sea level and to the postglacial sea level rise as on many passive margins.

Paleomagnetism of the Chiapas Massif, southern Mexico: Evidence for rotation of the Maya Block and implications for the opening of the Gulf of Mexico

We have analyzed 180 oriented samples of the batholithic complex and overlying red beds of the Chiapas Massif in southern Mexico for a paleomagnetic study. Both stepwise alternating-field and thermal demagnetization procedures revealed dual-polarity characteristic magnetizations above 10-30 mT or 200-400 °C in about 60% of the samples demagnetized. Three distinct and ancient paleomagnetic directions have been identified. Late Permian intrusions (256 ± 10 Ma) yield nearly equatorial southern hemisphere paleolatitudes and a paleopole (13.4°S,176.1°E; 12 sites, K = 15.4, A95 = 11.4°) rotated ∼75°, counterclockwise, with respect to the North American reference pole. A selected set of Late Triassic(?)-Jurassic red beds of the Todos Santos Formation yields a paleopole at 22.6°N, 170.6°E (4 sites, K = 56.8, A95 = 12.3°), which implies ∼60° counterclockwise rotation, and a near equatorial northern hemisphere paleolatitude. Middle-Late Jurassic dikes and granites yield a paleopole at 77.4°N, 97.4°E (6 sites, K = 269.2, A95 = 4.1°) near the Mid-Jurassic segment of the North American apparent polar wander path. These data are consistent with a pre-rift configuration in which the Maya Block is rotated to a position off the coast of Texas and Louisiana in the present-day area of the Gulf of Mexico. A further implication is that by Oxfordian times, Chiapas (and by inference the Maya Block) was essentially in its current position with respect to cratonic North America.

Neogene north American-Caribbean plate boundary across Northern Central America: Offset along the polochic fault

Abstract The Polochic fault was a segment of the North American-Caribbean plate boundary across Central America in the Neogene. Its 130 km of left slip was previously determined by matching structures and stratigraphie outcrop patterns of northwest and central Guatemala across the fault. Additional support for the model and the youthfulness of the recorded offset comes from an essentially perfect match of major geomorphic features across the fault. A reconstruction process which eliminates 123 km of left slip brings together rivers and drainage divides that existed before the Polochic became active. With the reconstruction carried across the isthmus on an east-west fault the regional structural geology assumes the coherent pattern of a continuous orogenic belt whose geometry is compatible with the model of collisional tectonics centered on the Motagua “suture zone”. Confined within this belt, narrowed to some 60 km by the reconstruction, lie the major Laramide thrusts, folds and tectonically emplaced serpentinites of Guatemala. Crystalline rocks of Guatemala re-join the Chiapas Massif and Paleozoic sedimentary rocks, exposed in the core of an almost-continuous anticlinorium, extend from southern Chiapas to Lake Izabal. The Polochic does not bend in eastern Guatemala but continues eastward to the Motagua fault where it dies. Westward drift of the northern block resulted in rifting which extended from eastern Guatemala into the Caribbean along the Cayman trough. The Honduras depression may represent an element of a triple junction along with the Polochic and Izabal-Cayman rift. The Polochic continues westward into the Pacific Ocean and offsets the Middle America trench. The Polochic has offset the Miocene volcanic belt of northern Central America, confirming the previous estimate of a Neogene time of movement. About 300 km of relative east-west Neogene displacement has been recorded on the Mid-Cayman rise, only 130 km of which can be accounted for across the Polochic. It is suggested that cumulative extension on north-south faults south of the Motagua fault zone between the trench and the Honduras depression might make up that difference.

Offset across the Polochic fault of Guatemala and Chiapas, Mexico

Research Article| June 01, 1978 Offset across the Polochic fault of Guatemala and Chiapas, Mexico Burke Burkart Burke Burkart 1Department of Geology, University of Texas at Arlington, Arlington, Texas 76019 Search for other works by this author on: GSW Google Scholar Author and Article Information Burke Burkart 1Department of Geology, University of Texas at Arlington, Arlington, Texas 76019 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1978) 6 (6): 328–332. https://doi.org/10.1130/0091-7613(1978)6<328:OATPFO>2.0.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Burke Burkart; Offset across the Polochic fault of Guatemala and Chiapas, Mexico. Geology 1978;; 6 (6): 328–332. doi: https://doi.org/10.1130/0091-7613(1978)6<328:OATPFO>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Polochic fault is seen on LANDSAT imagery to continue its westward path from northwestern Guatemala across the Chiapas massif to the Pacific coastal plain. The fault has had 132 ± 5 km of left-lateral displacement that is recorded in the offset of Cenozoic fold and thrust belt structure and stratigraphy. The trace of the Polochic fault has been folded into what approximates a sinusoidal curve of about 130-km wave length and 7-km amplitude by an essentially east-west compressive stress. The curious similarity in displacement and fold wavelength results in a premovement reconstruction that reveals not only a match across the fault in geology, but an almost perfect fit of one block against the others. Some segments of the fault across which recorded slip took place are probably locked and not active. Strain has shifted to other shears in western Guatemala and Chiapas and to the Motagua fault. Parts of the Polochic and the newer shears may be alternating with the Motagua as the Caribbean-North American plate boundary. With the 132 km of slip removed, segments of the now fragmented Cenozoic fold belt can be brought into coincidence in a clear-cut arcuate trend that is convex southwest. The major fault displacement is believed to have occurred within the interval from middle Miocene to middle Pliocene time. Eastern Guatemala has undergone a counterclockwise rotation of about 25° that reoriented the fault trace and all other structural fabric from due east to the present east-northeast azimuth. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.